1. Field of the Invention
The present invention involves liquid dispensers which rely upon pump action by a user for dispensing liquids such as creams and lotions. More particularly, the present invention relates to a double action dispenser, i.e., one which dispenses liquid both when the actuator moves downward and when the actuator moves upward. The present invention dispensers eliminate a number of parts and significantly reduce valve friction and wearing of components compared to the Prior Art devices.
2. Information Disclosure Statement
Various double action sprayers have been developed over the years and the Academy of Sciences of Czechoslovakia developed a double action liquid atomizer and a double action trigger sprayer liquid atomizer. These are described in the patent literature as follows:
U.S. Pat. No. 4,503,996 issued to Miloslav Sorm et al. describes a liquid atomizer having a reciprocable pump. The atomizer provides a reliable sealing of the piston rod of the pump with lowered requirements as to the manufacturing tolerances of parts, a simplified manner of venting, and the sealing of the atomizer against leakage when the atomizer is placed in any arbitrary rest position. A sleeve having a smaller inner diameter than the cylinder is mounted on the upper part of the cylinder of the pump and its upper part is in contact with the inner part of a neck of a housing for the atomizer. A free space between the inner wall of the housing and the outer wall of the cylinder of the pump is connected below with the interior of the bottle on which the atomizer is mounted, and the upper part of the free space communicates with the surface of a tube by radial channels passing through the sleeve of the cylinder. The tube slidingly passes through the neck of the housing, is connected on the top with an operating button, and ends below with a sealing cuff piston which covers, when in its upper position, the radial channels and, at the same time, bears by its upper part on the neck of the housing. The tube forms a part of a narrow upper part of a piston rod which reciprocates through the sleeve, whereas the lower broadened part of the piston rod bears the piston of the pump and a one-way valve.
U.S. Pat. No. 4,646,969 issued to Miloslav Sorm et al. describes a double-acting mechanical liquid spraying device having a housing which is adapted to be mounted upon and sealed to the neck of a liquid container, and which has a liquid-containing compartment therein. In the housing, aligned with the liquid-containing compartment, there is an operation cylinder which has an annular valve seat disposed transversely to and to an intermediate length of such cylinder. Disposed within the liquid-containing compartment is a liquid pumping plunger of the cuff type which cooperates with the valve seat to close the opening through such seat when the plunger is in its forward terminal position, and which is driven to reciprocate within the liquid-containing compartment in forward and reverse liquid dispensing strokes. In each of such strokes the plunger forwards liquid from the liquid-containing compartment to a spray nozzle through a liquid-conducting passage. Interposed in the liquid-conducting passage between the plunger and the spray nozzle are a relief valve and a relief passage which bleed liquid back to the liquid container and allow atmospheric air to be drawn in through the spray nozzle at the end of the reverse stroke of the plunger, thereby to clear the spray nozzle of liquid at the end of each pumping cycle consisting of a forward and a reverse stroke. As a consequence, fast-drying liquids can be sprayed with the device of the invention.
The commercial embodiments of the vertical reciprocal sprayer of U.S. Pat. No. 4,503,996, included visions in which the spray nozzles were replaced with tube nozzles for liquid dispensing without spraying, e.g. for creams and lotions.
Notwithstanding the above prior art, there are no teachings or suggestions that would render the present invention anticipated or obvious. In fact, the Czech double action sprays and liquid dispensers rely upon a cuff type piston and valve and this cuff acts as a valve by being spread open on the upstroke so as to prevent passage of liquid past it and squeezed closed on the downstroke so as to permit liquid to pass by it. However, this cuff acts as a valve with its seat being essentially the side walls of the chamber. In other words, the cuff and chamber walls move relative to one another and this abrasion causes leakage, unusual wear and sometimes volume problems. Thus, the present invention is directed to overcoming these shortcomings of the aforesaid prior art.